1. Field of the Invention
The present invention relates to optical scanner that has two rotation disks to respectively carry a plurality of different lenses and Charge-Coupled Devices (CCD) for adjusting resolution by changing lens and CCD combination so that users may select different resolutions to meet different scanning requirements.
2. Description of the Prior Art
Optical technology innovation in the past century has spawned numerous optical products to benefit human being, ranging from spectacles, telescope, to conventional or digital camera, copy machine, monitor and scanner. Scanner is an important optical device nowadays. It can scan important image or text data files into computer. Then image and data may be processed or edited for display or presentation use. It saves a lot of data input and process time. Scanner quality and value highly depends on its resolution. Conventional scanner usually has only one lens and one CCD for scanning in a selected resolution. Such a design and structure has severely limited its application and usefulness. When there is a need for scanning of different resolutions, different sets of scanner equipped with different resolutions will be needed. Users have to invest a lot more money to acquire many different scanners. Scanning operation is more difficult to arrange and become less efficient. Scanner manufacturers have to design and produce a lot more different scanners to meet market needs. It adds more research and development costs. All this begs for improvement.
The present invention aims at resolving a common problem existed in conventional scanners which have only one set of optical focusing means and cannot provide scanning for documents of various resolutions. The present invention offers a novel structure to attack the deficiency of conventional scanners. The scanner according to the present invention has an additional transmission motor attached with a transmission gear for driving a transmission shaft. The transmission shaft has two one-way shaft bearings mounted thereon. At any one time, only one set of the one-way shaft bearings may receive force and turn when driven in a positive or reverse direction. The two one-way shaft bearings engage with the gears of two rotational disks. The rotational disks have respectively a center engaged with a spindle through a one-way spindle bearing. The spindle has one end fixedly engaged with an inner wall of the scanner. A first rotational disk has a plurality of lenses located thereon. A second rotational disk has a plurality of CCD located thereon. When the motor rotates in positive or reverse direction, the two disks may be turned respectively at two opposite directions (one clockwise, another counterclockwise) to adjust relative position between each other such that the lens and CCD may be aligned to different combinations. Then focus of different resolutions may be obtained for users to choose the optimum combination to suit their requirements.
In one aspect, the lenses on the first rotational disk may have different focuses. The first rotational disk may be turned to position a lens on the optical path to pair with a stationary CCD for obtaining a selected resolution.
In another aspect, each CCD has different resolution. And the second rotational disk may be turned to move a selected CCD on the optical path to pair with a stationary lens for obtaining an optimum focus.